Problem Solving
试题详情
题目：
Of the 150 houses in a certain development, 60 percent have air- conditioning, 50 percent have a sunporch, and 30 percent have a swimming pool. If 5 of the houses have all three of these amenities and 5 have none of them, how many of the houses have exactly two of these amenities?
选项:
A、10
B、45
C、50
D、55
E、65
答案:
D
